Cyanuric chloride which is recovered by trimerization of cyanogen chloride with the help of catalyst, above all activated carbon, as is known is a very interesting intermediate product for various industrial sectors such as the production of dyestuffs and products for the textile industry, as well as for pharmaceuticals, products for agriculture as well as for the synthetic resin, rubber and explosives industries.
As is known after the trimerization cyanuric chloride is obtained in gaseous form together with unreacted cyanogen chloride and chlorine as well as byproducts.
For a long time, it was customary to convert this gaseous reaction mixture directly into solid cyanuric chloride, e.g., by conducting the gaseous mixture into a chamber cooled from the outside (see Ullmann, Enzyklopadie der technischen Chemie, 3rd Edition, 1954, Volume 5, pages 624-625 and 4th Edition, 1975, Volume 9, page 652).
It has also been passed into a ball mill cooled with water according to the process of Trickey U.S. Pat. No. 3,256,070.
Solid cyanuric chloride generally is obtained in powdery form and until now was predominantly further processed in this form.
A disadvantage of the solid cyanuric chloride, however, is that it is frequently not simple to handle.
In filling containers and storing as well as in further processing it precautions were necessary.
Besides there are certain industrial difficulties connected with the deposition in solid form since the cyanuric chloride deposits partially in the form of coarse crystals on the walls and installations in the deposition receiver and delivery aggregate.
These coarse crystals must be knocked off mechanically and then led to a clear impairment of the quality of the final product.
In order to avoid the deposition of coarse crystals inert cooling liquids have been sprayed via nozzles in the deposition of the solid cyanuric chloride, see German Pat. No. 1,266,308 and related Kosel U.S. Pat. No. 3,409,619.
However, in connection therewith there occurs encrustations on the nozzles and cloggings.
For reasons of work hygiene and environmental protection as well as with the coming into use of ever increasing automatic processes it was necessary to recover cyanuric chloride in a form better to handle and to process.
Cyanuric chloride in liquid or dissolved form offers a way of doing this. The presence of cyanuric chloride in dissolved form, however, requires a fairly large expense for the manufacture and recovery of the solvent.
Besides there occur waste gas problems which additionally complicate the process, see Evers U.S. Pat. No. 3,539,565.
The solvent used in each case also must be adjusted according to the later intended area of use and the solubility of cyanuric chloride in the individual solvents is quite varied.
Furthermore there are known processes in which gaseous cyanuric chloride is liquefied with the help of a liquid assistant. These liquid assistants, as e.g., phosphorus oxychloride should prevent the cyanuric chloride from passing out of the fractionating column.
However, the use of such a liquid assistant requires an expensive apparatus for working up and recycling the liquid assistant employed, as well as for purification of the waste gas.
Furthermore it has been shown that accidental break through of the liquid assistant into the liquid cyanuric chloride phase leads to considerable loss of quality.
Besides because of the increasing importance of the liquid cyanuric chloride and the high market share of powdery cyanuric chloride it would be desirable if a process existed according to which both phases could be recovered in the same apparatus and in a simple manner.
Thus the object of the invention is to develop a process for the production of cyanuric chloride in which the cyanuric chloride can be recovered substantially at will in liquid or solid form.